custom theme not showing in admin panel

I created a new theme for the mobile version of the blog but it doesn’t show up in the admin panel.
The folder with the css and the other template files is in wp-admin/themes/
on top of the style sheet I put `/*
Theme Name: mobile
Theme URI: http://wordpress.org/
Description:
Author:
*/`
like its said on the doc page about themes to get recognized.
However nothingis showing.

I didn’t had this problem before because I built the main template on top of the default one modifying it. I thought I would have changed the name as last thing.

Why my “mobile” theme isn’t showing? what should I add?

Thanks to everyone